Решите: (a-5) (a-3)=a^2-3a-5a+15=a^2-8a+15

Question

Решите: (a-5) (a-3)=a^2-3a-5a+15=a^2-8a+15

Answer 1

D=8^2-4*15=64-60=4=2^2
a1= -8 + 2/2=-6/2=-3
a2=-8-2/2=-10/2=-5